In tonight's ( Wednesday )episode of the soap Alma Halliwell, played by Amanda Barrie, reveals her fears that she has cancer after being the subject of a smear test mix-up.

But today experts were seeking to reassure women that regular smear tests are the best way to prevent cervical cancer, and urging them to always have their checks.

Prof Gordon McVie, Director General of the Cancer Research Campaign, said: "I am extremely supportive of the way soaps are prepared to tackle difficult cancer issues. But because of its controversial nature, I will be monitoring this storyline with some concern."

He accepted that the screening programme has not been without problems, but stressed that smear tests can detect changes before cancer starts.

"My advice is to keep both your screening appointments and your faith in the system," he said.

Around 3,000 cases of cervical cancer are diagnosed each year in the UK, with nearly 1,300 dying from the disease.

screening saves lives

Carole Walker, the laboratory manager of the Manchester Cytology Centre said: "The NHS screening programme saves around 1,300 lives a year. It is directly responsible for a 42 per cent drop in the incidence of cervical cancer between 1988 and 1997, when it saved more than 8,250 lives.

"A cervical smear test is simple and painless. There are many risk factors involved in cervical cancer but the greatest one is failing to have regular smears.

"The sooner an abnormality is found, the easier it is to treat and the risk of cervical cancer is greatly reduced."

The Manchester centre which includes the Christie Hospital, is at the forefront of assessing new screening technology and is currently involved in a trial of 30,000 women.

However, a spokeswoman for Granada defended the storyline, saying it had been thoroughly researched and checked with experts at the Christie.

"Cancer consultants have read the script, and whilst Alma's is an extreme case, and would be fairly rare, it is absolutely medically accurate," she said.